On Wed, 26 Aug 2020 at 17:50, David Mertz <me...@gnosis.cx> wrote: > > In my mind, *anything* other than the straightforward and obvious signature > `__getitem__(self, index, **kws)` is a pointless distraction.
It isn't. and the reason why it isn't is that it makes it much harder for the implementing code to decide how to proceed, for the following reasons: 1. you will have to check if the keywords you receive are actually in the acceptable set 2. you will have to disambiguate an argument that is supposed to be passed _either_ as position or with keyword. Always remember this use case: a matrix of acquired data, where the row is the time and the column is the detector. I've seen countless times situations where people were creating the matrix with the wrong orientation, putting the detector along the rows and the time along the column. so you want this acquired_data[time, detector] to be allowed to be written as acquired_data[time=time, detector=detector] so that it's unambiguous and you can even mess up the order, but the right thing will be done, without having to remember which one is along the row and which one is along the column. If you use the interface you propose, now the __getitem__ code has to resolve the ambiguity of intermediate cases, and do the appropriate mapping from keyword to positional. Which is annoying and you are basically doing manually what you would get for free in any standard function call. Can you do it with that implementation you propose? sure, why not, it's code after all. Is it easy and/or practical? not so sure. Is there a better way? I don't know. That's what we are here for. To me, most of the discussion is being derailed in deciding how this should look like on the __getitem__ end and how to implement it, but we haven't even decided what it should look like from the outside (although it's probably in the massive number of emails I am trying to aggregate in the new PEP). -- Kind regards, Stefano Borini _______________________________________________ Python-ideas mailing list -- python-ideas@python.org To unsubscribe send an email to python-ideas-le...@python.org https://mail.python.org/mailman3/lists/python-ideas.python.org/ Message archived at https://mail.python.org/archives/list/python-ideas@python.org/message/QQBD4LNE46C7NIKSH5VWT7MBTJYTMHNB/ Code of Conduct: http://python.org/psf/codeofconduct/
